How do you alert the users that are running the problematic software and haven't yet updated it? The very premise is ridiculous.
Where did you get the weird idea the software isn't updated? This entire discussion is about deprecation of older encryption methods in new versions of software.
Yes, but that is only needed to connect with old software that has not updated. Two pieces of new software will not negotiate on using old crypto even if they both support it.
In the trouble situations, one of the two pieces of software being upgraded is thrust upon the user.
Where did you get the weird idea the software isn't updated? This entire discussion is about deprecation of older encryption methods in new versions of software.
You're not giving this thought. Good day.